The purpose of this study is to develop an instrument for the evaluation of abdominal pain in cystic fibrosis patients which would be useful to clinicians in their evaluation of these patients and to epidemiologists in their studies of cystic fibrosis gastrointestinal disease. A second objective is to correlate the answers on the questionnaire with the results of several tests of the blood, urine and stool which check for routine complications of cystic fibrosis.